Stain removing composition

ABSTRACT

A COMPOSITION FOR REMOVING STAINS WHICH CONTAINS A PROTEOLYTIC ENZYME, A HYDROXYLAMINE COMPOUND OR A HYDRAZINE COMPOUND HAVING AT LEAST ONE FREE HYDROGEN ON THE HYDROXYLAMINE OR HYDRAZINE NUCLEUS, A PERBORATE AND AN ACTIVATOR FOR THE PERBORATE.

United States Patent US. Cl. 252-95 7 Claims ABSTRACT OF THE DISCLOSURE A composition for removing stains which contains a proteolytic enzyme, a hydroxylamine compound or a hy-' drazine compound having at least one free hydrogen on the hydroxylamine or hydrazine nucleus, a perborate and an activator for the perborate.

This invention relates to stain removal and detergency.

The use of proteolytic enzymes as assistants in the laundering of clothes with detergent compositions has long been known in the art. While combination contining both enzymes and sodium perborate, a well known bleaching agent used in detergent products, have been suggested, the art has taught that the presence of the perborate has an inhibitory effect on the enzyme action, which inhibitory action passes away, in part after some time (e.g. on soaking overnight in the presence of the detergent composition). The use of bleaches of greater activity than sodium perborate, such as chlorine bleach'es (supplied for instance by the use of a chloroisocyanurate material which yields hypochlorous ions in the wash water) has a marked inhibiting effect on the stain-removing activity of detergent products containing enzymes.

In accordance with certain of its aspects, this invention relates to a novel and highly effective composition for removing stains in the washing of soiled laundry and fabrics which contain a proteolytic enzyme, a hydroxylamine compound or a hydrazine compound having at least one free hydrogen on the hydroxylamine or hydrazine nucleus, a perborate and an activator for the perborate. With the composition of the invention one can obtain in a short washing cycle, and at moderate washing temperatures, say 80 (3., improved removal of stains compared to when a component of the invention is omitted. The composition may also provide strong inhibition of activity during prewashing and permit a high retention of percompound after washing.

In the past, it has been proposed to include hydroxylamine or hydrazine compounds in compositions containing a perborate in order to inhibit formation of catalase which breaks down and reduces the effect of perborate. It would be thought that this would not be necessary in compositions containing an activator for the perborate since percompounds formed with activators are not as subject to substantial breakdown by catalase. However, it has unexpectedly been found that when perborate and activator are present together with a proteolytic enzyme, the degree of enzyme activity can be beneficially affected by including in the composition a hydroxylamine or hydrazine compound containing free hydrogen, even though such compounds have been thought to be unnecessary in activated perborate compositions. Further, the presence of the hydroxylamine or hydrazine compounds also serves to 3,725,289 Patented Apr. 3, 1973 reduce the amount of catalase formation which takes place even in activated perborate compositions.

The proteolytic enzymes which are employed in the instant invention are active upon protein matter and catalyze digestion or degradation of such matter when present as in linen or fabric stain in a hydrolysis reaction. The enzymes are effective at a pH range of about 4-12, such as usually prevails in detergent cleaning procedures. Moreover, they may be effective even at moderately high temperatures so long as the temperature does not degrade them. Some proteolytic enzymes are effective at up to about 80 C. and higher. They are also effective at ambient temperature and lower to about 10 C. Particular examples of proteolytic enzymes which may be used in the instant invention include pepsin, trypsin, chymotrypsin, papain, bromelin, colleginase, keratinase, carboxylase, amino peptidase, elastase, subtilisin and aspergillopepidase A and B. Pre ferred enzymes are subtilisin enzymes manufactured and cultivated from special strains of spore forming bacteria, particularly Bacillus subtilis.

Metalloproteases which contain divalent ions such as calcium, magnesium or zinc bound to their protein chains are of interest.

The enzyme preparations are generally extremely fine, often substantially impalpable, powders. In a typical powdered enzyme preparation the particle diameter is mainly below 0.15 mm. generally above 0.01 mm., e.g. about 0.1 mm.; for example, as much as of the material may be 0.149 mm. or smaller.

The enzyme preparations are generally diluted with salts such as calcium sulfate and inert materials. Chemically they are typically stable in the pH of 5 to 10 and at an alkaline pH of 8.5 to 9 they can withstand temperatures of 49 C. to 77 C. with relatively little decomposition for time periods varying from 2 hours at the higher temperatures to more than 1 day at the lower temperatures. Different proteolytic enzymes have different degrees of effectiveness in aiding in the removal of stains from textiles and linen.

The enzyme is preferably present in powdered form and is admixed into the formulation. It is typically present in amount of about 0.001%4% by weight of the composition, preferably about 0.051%, e.g. about 0.10.5%.

The hydroxylamine compound or hydrazine compound may be added as such or in the salt form, e.g. as the hydrochlorides, sulfates, nitrates, phosphates, fluorosilicates, formates, or oxalates. Hydroxylamine, hydrazine, phenyl hydrazine, carbamoyl hydrazine, N-phenyl-N-carbamoylhydrazine are examples of suitable compounds. When substituted hydroxylamine or hydrazine compounds are employed, they should retain at least one unsubstituted hydrogen on the hydroxylamine or hydrazine nucleus; thus, mono, dior tri-substituted hydrazine may be used. The substituent, or substituents, may be alkyl, e.g. methyl or butyl, or aryl, e.g. phenyl, or of other types, e.g. carbamyl.

The hydroxylamine compound or hydrazine compound is employed in amount of about 1 to 10% of the composition.

The perborate compound which is employed in the practice of this invention is typically present in amount of about 3 to 35% by weight. The compound may be alkali metal perborate such as sodium perborate tetrahydrate or sodium perborate monohydrate.

The perborate activators are a well known class of materials. The perborate activators of greatest importance in the practice of this invention are compounds which are carboxylic acid precursors. Such compounds include esters and anhydrides and acyl amides. Examples of suitable activators include the following:

N-p-chlorobenzoyl phthalimide etc.

Further examples of suitable activator compounds of the imide type, both cyclic and aliphatic, have the following structural formula:

R1(]OR wherein R represents alkyl and preferably lower alkyl of 1 to 4 carbon atoms or aryl such as phenyl and R represents an N-bonded imide radical. Thus, included within the foregoing structural formula are the following:

N-methoxycarbonyl saccharide N-methoxycarbonyl phthalimide N-ethoxycarbonyl phthalimide N-methoxycarbonyl-S,S-dimethyl hydantoin N-methoxycarbonyl succinimide N-phenoxycarbonyl succinimide N,N-di-(methoxycarbonyl) acetamide N-methoxycarbonyl glutarirnide l, 3-di- N-methoxycarbonyl -hydantoin 1, 3-di-(N-methoxycarbonyl)-5-dimethyl hydantoin Other suitable activator compounds are represented according to the following structural formula:

KC \Z/ wherein X represents halogen e.g. chloro and Z represents the atoms necessary to complete a heterocyclic nucleus selected from the group consisting of hydantoin and succinimide.

Specific representatives of compounds of this type include, without necessary limitation, the following:

N-m-chlorobenzoyl-S,S-dimethyl hydantoin N-m-chlorobenzoylsuccinimide etc.

Another group of activator compounds comprises N- sulfonated cyclic imides including those of the following structural formula:

wherein R represents lower alkyl of from 1 to 4 carbon atoms and aryl and Z represents the atoms necessary to complete a heterocyclic ring selected from the group consisting of succinimide and phthalimide. Specific examples of compounds of this type include, without necessary limitation, the following:

N-benzenesulfonyl phthalimide N-benzenesulfonyl succinimide N-methanesulfonyl phthalimide N-methanesulfonyl succinimide A further class of activator compounds comprises alkyl and aryl chloroformate derivatives, including for example:

Methylchloroformate Ethylchloroformate Phenylchloroformate Activator compounds which are particularly effective in increasing the effectiveness of cleaning of soiled clothes are tetraacetylmethylenediamine, ethylsulfophenyl car- 'bonate, trisacetyl cyanurate and acetylsalicylic acid.

A preferred range of proportions of the perborate is one which provides a concentration of per compound in the wash water equivalent to about 1 to 150 p.p.m., more preferably about 10 to p.p.m., e.g. 30 to 75 ppm, of available oxygen; about 40-50 p.p.m has given best results. In sodium perborate tetrahydrate (NaBO AH o) the available oxygen content (or peroxy oxygen content) is about 10%; Le. one atom of available oxygen per molecule of the perborate. The proportions of perborate for use in the detergent formulation can therefore readily be calculated if one knows how much of the total formulation is to be added to the wash water. Commercial detergent formulations are often designed for use in proportions in the range of about 0.1-1.5% in the wash water (e.g. at 0.151% concentration), a preferred detergent formulation containing sodium perborate tetrahydrate designed for use at the 0.5% concentration in the wash water will therefore contain approximately 5 to 15% of that compound, corresponding roughly to the 8 to 75 p.p.m. of available oxygen.

Since individual activators vary in structure and molecular weight as well as performance, it is convenient to relate the quantity of activator to be employed to the desired available oxygen present in the particular percompound being used. For reactive aromatic mono-acyl compounds such as meta-chlorobenzoyldimethylhydantoin and meta-chlorobenzoylsuccinimide, strong bleaching is obtained when approximately equimolecular quantities of activator and peroxygen are present. Bleaching is enhanced with increase in the concentration of activator and maintenance of about 1:1 mol ratio of activator and the peroxygen present in the per-compound. By increase of the mol ratio of available oxygen to activator, milder bleaching is obtained particularly when the ratio is greater than 2:1. For reactive aliphatic polyacylated compounds such as tetra-acetylethylenediamine, tetra-acetylhydrazine, triacetyl cyanurate, the mol ratio of available oxygen to activator is preferably 2:1, although higher (e.g. 6:1) or lower (e.g. about 1:1 or less) mol ratios may be employed.

The enzyme, hydroxylamine compound or hydrazine compound, perborate and activator may be used together in water for a pre-wash or soaking of soiled clothes with or without the presence of surface-active detergent. The composition may also be used in a washing detergent composition, such as a heavy-duty built granular detergent.

The surface active agent which may be employed may be any commonly used compound having surface active or detergent properties. Most preferred are those watersoluble surface active compounds having anionic or nonionic properties. Anionic surface active agents include those surface active or detergent compounds which contain an organic hydrophobic group and an anionic solubilizing group. Typical examples of anionic solubilizing groups are sulfonate, sulfate, carboxylate, and phosphate. Examples of suitable anionic detergents which fall within the scope of the invention include the soaps, such as the water-soluble salts of higher fatty acids or rosin acids, such as may be derived from fats, oils and waxes of animal, vegetable or marine origin, e.g., the sodium soaps of tallow, grease, coconut oil, tall oil and mixtures thereof; and the sulfated and sulfonated synthetic detergents, particularly those having about 8 to 26,

and preferably about 12 to 22 carbon atoms to the molecule.

As examples of suitable synthetic anionic detergents there may be cited the higher alkyl mononuclear aromatic sulfonates such as the higher alkyl benzene sulfonates containing from to 16 carbon atoms in the alkyl group in a straight or branched chain, e.g., the sodium salts of decyl, undecyl, dodecyl (lauryl), tridecyl, tetradecyl, pentadecyl, or hexadecyl benzene sulfonate and the higher alkyl toluene, xylene and phenol sulfonates; alkyl naphthalene sulfonate, ammonium diamyl naphthalene sulfonate, and sodium dinonyl naphthalene sulfonate; sulfated aliphatic alcohols such as sodium lauryl and hexadecyl sulfates, triethanolamine lauryl sulfate and sodium oleyl sulfate; sulfated alcohol ethers, such as lauryl, tridecyl, or tetradecyl sulfates including 2-4 ethylene oxide moieties; sulfated and sulfonated fatty oils, acids or esters such as the sodium salts of sulfonated castor oil and sulfated red oil; sulfated hydroxyamides such as sulfated hydroxyethyl lauramide; sodium salt of laurylsulfoacetate; sodium salt of dioctyl sulfosuccinate; and the sodium salt of oleyl methyl tauride.

Other anionic surface active agents which may be employed in the practice of this invention include olefin sulfonates, typically containing 8-25 carbon atoms.

Also included within the ambit of the invention are the sulfuric acid esters ofapolyhydric alcohols incompletely esterified with higher fatty acids, e.g. coconut oil monoglyceride monosulfate, tallow diglyceride monosulfate; and the hydroxy sulfonated higher fatty acid esters such as the higher fatty acid esters of low molecular weight alkylol sulfonic acid, e.g., oleic acid ester of isethionic acid.

Nonionic surface active agents are those surface active or detergent compounds which contain an organic hydrophobic group and a hydrophilic group which is a reaction product of a solubilizing group such as carboxylate, hydroxyl, amido or amino with ethylene oxide or with the polyhydration product thereof, polyethylene glycol.

As examples of nonionic surface active agents there may be noted the condensation products of alkyl phenols with ethylene oxide, e.g., the reaction product of isooctyl phenol with about 6 to 30 ethylene oxide units; condensation products of alkyl thiophenols with 10 to ethylene oxide units; condensation products of higher fatty alcohols such as tridecyl alcohol with ethylene oxide; ethylene oxide addends of monoesters of hexahydric alcohols and inner ethers thereof such as sorbitan monolaurate, sorbitol mono-oleate and mannitan monopalmitate and the condensation products of polypropylene glycol with ethylene oxide.

Cationic surface active agents may also be employed. Such agents are those surface active detergent compounds which contain an organic hydrophobic group and a cationic solubilizing group. Typical cationic solubilizing groups are amine and quaternary groups.

As examples of suitable synthetic deter-gents there may be noted the diamines such as those of the type wherein R is an alkyl group of about 12 to 22 carbon atoms, such as N-aminoethyl staryl amine and N-aminoethyl myristyl amine; amide-linked amines such as those of the type R'CONHC H NH wherein R is an alkyl group of about 12 to 18 carbon atoms, such as N-amino ethyl stearyl amide and N-amino ethyl myristyl amide; quaternary ammonium compounds wherein typically one of the groups linked to the nitrogen atom is an alkyl group of about 12 to 13 carbon atoms and three of the groups linked to the nitrogen atom are alkyl groups which contain 1 to 3 carbon atoms, including such 1 to 3 carbon alkyl groups bearing inert substituents, such as phenyl groups and there is present an anion such as halogen, acetate, methosulfate, etc. Typical quaternary ammonium detergents are ethyl-dimethyl-stearyl ammonium chloride,

benzyl-dimethyl stearyl ammonium chloride, trimethylstearyl ammonium chloride, trimethyl-cetyl ammonium bromide, methyl-ethyl-dilauryl ammonium chloride, dimethyl-propyl-myristyl ammonium chloride, and the corresponding methosulfates and acetates.

The surface active compounds which are used in the most preferred aspects of this invention are those having anionic or nonionic properties. The most highly preferred Water soluble anionic detergent compounds are the ammonium and substituted ammonium (such as mono-, diand triethanolamine), alkali metal (such as sodium and potassium) and alkaline earth metal (such as calcium and magnesium) salts of the higher alkyl benzene sulfonates, the higher alkyl sulfates, and the higher fatty acid monoglyceride sulfates. The particular salt will be suitably selected depending upon the particular formulation and the proportions therein.

The surface active agent is typically present in amount of about 5-95 by Weight of the detergent composition, preferably 10-25% by weight.

In addition to the materials described above, the detergent composition of the invention may include a builder for the detergent. The builder may be any of the watersoluble inorganic builder salts commonly known in the art, or it may be a water-soluble organic sequestering agent such as sodium nitrilotriacetate, or mixtures thereof.

The water-soluble inorganic builder salts may be suitable alkali metal, alkaline earth metal, or heavy metal salt or combinations thereof. Ammonium or an ethanolammonium salt in a suitable amount may be added also, but generally the sodium and potassium salts are preferred. Examples are the Water-soluble sodium and potassium phosphates, silicates, carbonates, bicarbonates, borates, sulfates and chlorides. Particularly preferred builder salts are the alkaline builder salts such as polyphosphates, silicates, borates, etc.

In the water-soluble inorganic builder salt mixtures used in the detergent compositions, it is often preferred to have present a mixture of sodium tripolyphosphate and sodium or potassium bicarbonate, such as a combination or mixture of salts wherein the bicarbonate to tripolyphosphate ratio is selected from the range of about 1:1 to about 3:1.

Both Phase I and Phase II sodium tripolyphosphate and mixtures thereof may be successfully used in the compositions. The usual commercial tripolyphosphate consists mainly of the Phase II material. The commercial tripolyphosphate is usually essentially tripolyphosphate, e.g. 87-95%, with small amounts, e.g. 4-13% of other phosphates, e.g. pyrophosphate and orthophosphate. Sodium tripolyphosphate in its hydrated form may be used also. Trisodium orthophosphate may be used in the amounts indicated.

The sodium or potassium bicarbonate is an effective pH buffer. The bicarbonate may be incorporated directl as anhydrous bicarbonate or in the form of sesquicarbonate, a hydrate containing both bicrabonate and carbonate.

Other suitable builder salts which may be present include the water-soluble sodium and potassium silicates, carbonates, borates, chlorides and sulfates.

Generally, when present, the builder salt is employed in amount in the range of about 20-90%, preferably at least 25% (eg 35 to of the detergent composition.

The composition may also contain polymeric additives such as sodium carboxymethylcellulose of polyvinyl alcohol (eg. in amount of about (Ll-5%) or other polymeric additives to inhibit redeposition of soil. Minor amounts of optical brighteners may be present, as in proportions in the range of about 0.01 to 0.15%; examples of such brighteners are the stilbene brighteners such as sodium 2 sulfo 4 (2 naphtho 1,2 triazole) stilbene; disodium 4, 4-bis(4-anilino-6-morpholine-s-triazin-Z-yl amino) stilbene disulfonate or disodium 4,4

bis(4,6-dianilino-s-triazin-Zyl-amino) stilbenedisulfonate; and the oxazole brighteners, having for example a 1- after cleaning. The average increases in reflectance obtained with each composition are:

phenyl-Z-benzoxazole ethylene structure. Perfumes, coloring agents and preservatives may also be included.

The enzyme, hydroxylamine compound or hydrazine compound, perborate and activator may be added in powdered form to the detergent composition and mixed therewith, as by dry blending. To improve the stability of the compositions, one or more of these ingredients may be protected from the atmosphere or from contact with the others. For example, the perborate or the activator or the enzyme or each of them may be encapnlated or agglomerated by means of a coating of a protective material such as polyvinyl alcohol, a long chain fatty acid (e.g. lauric or stearic) or an amide thereof, a paraffin or a water-soluble or water-dispersible polyethylene glycol (e.g. a solid Carbowax). It is also within the broader scope of the invention to supply separate packets (e.g. in moisture proof wrappings) of these ingredients for addition to the wash water.

The compositions of this invention may be used for washing for short periods, e.g. 5 to 45 minutes, in cool water, e.g. at 25-40 C. or in warmer water, e.g. at 45- 80 C. They may also, if desired, be used for soaking at room temperature or in warm water for several hours or overnight.

The following example is given to illustrate this invention further. In the example, as in the rest of the application, all proportions are by weight unless otherwise indicated.

EXAMPLE Twenty-four loads of soiled clothes, each load including one multi-stained EMPA strip and each load weighting about 3 kilograms is placed in an automatic Miele washing machine and then prewashed with 100 g. of each of the following compositions (each composition being used in 12 machines) in 20 liters of Water at room temperature for 20 minutes.

Parts Composi- Composition A tion B Sodium dodeeylbenzone sultonate 3 3 C -C13 ethoxylated fatty alcohol (50 E) 6 6 Tallow soap 5 5 Sodium tripolyphosphate 40 40 Sodium silicate 6 6 Optical brighteners. 0. 5 0. 5 Sodium carboxymethyl cellulose. 1 1 Subtilisin enzyme (Alcalase) 6. 35 6. 35 Sodium perborate tetrahydratm... 10 Ethyl sulfophenyl carbonate 15. 7 15. 7 Hydroxylamine sulfate 1. 2 Sodium sulfate, moisture, perfume, etc

1 Q.S. to 100.

The enzyme Alcalase is characterized as having its maximum proteolytic activity at a pH of 89. The activity as measured on the commercial enzyme available from Novo Indnstri A/S, Copenhagen, Denmark, is about 1.5 Anson Units per gram of the enzyme. Granulated enzyme is employed in the instant composition which provides about 0.7 parts of Alcalase per 100 parts of the composition.

Following the prewash cycle the clothes and EMPA strip in each machine are washed with 100* grams the same composition employed in the prewash in liters of water at 60 C. for minutes.

The stain removal from the twelve EMPA strips which had been cleaned with each composition was determined by averaging the increase in reflectance (Rd) obtained The composition B of the instant invention was significantly better than composition A in over-all stain removal. Furthermore, there was little catalase formation and desirable amounts of percompound remained available after washing.

Similar desirable stain removal is obtained with compositions containing proteolytic enzyme, a perborate and an activator for the perborate when hydrazine, phenyl hydrazine, N-phenyl-N carbamoyl hydrazine and the like replace the hydroxylamine compound.

Likewise, desirable stain removal is obtained with compositions in which ethyl sulfophenyl carbonate is replaced with other activators such as tetraacetylmethylene diamine, triacetyl cyanurate and acetyl salicylic acid, and in which Alcalase is replaced by other proteolytic enzymes such as Maxatase available from Royal Netherlands Fermentation Industry Ltd., Delft, Netherlands.

Many additional variations may be made herein without departing from the spirit of the invention.

I claim:

1. In a composition for removing stains consisting essentially of about 0.001%4% by Weight of a proteolytic enzyme, about 335% by Weight of an alkali metal perborate, and an activator for the perborate containing a carboxylic acyl group, said perborate being one which reacts with said activator to form the corresponding percarboxylic acid when said composition is added to wash water; wherein the mole ratio of available oxygen in said perborate to said activator is about 1:1 to about 6: 1, the improvement of including in said composition a compound selected from the group consisting of a hydroxylamine compound and a hydrazine compound, each having at least one free hydrogen on the hydroxylamine or hydrazine nucleus said compound being present in amount of about 110% by weight.

2. A composition for removing stains as claimed in claim 1 wherein a hydroxylamine compound having at least one free hydrogen on the hydroxylamine nucleus is employed.

3. A composition for removing stains as claimed in claim 2 wherein said hydroxylamine compound is hydroxylamine sulfate.

4. A composition for removing stains as claimed in claim 1 wherein a hydrazine compound having at least one free hydrogen of the hydrazine nucleus is employed.

5. A composition for removing stains as claimed in claim 1 wherein said perborate is sodium perborate.

6. A composition for removing stains as claimed in claim 1 wherein said activator for the perborate is selected from the group consisting of tetraacetylmethylene diamine, ethylsulfophenyl carbonate, trisacetyl cyanurate, and acetyl salicyclic acid.

7. A composition for removing stains as claimed in claim 6 wherein said activator for the perborate is ethylsulfophenyl carbonate.

References Cited UNITED STATES PATENTS 3,637,339 1/1972 Gray 252 3,348,903 10/ 1967 Baier 8-111 2,730,428 1/1956 Lindner 8-111 2,914,374 11/1959 Harris et al. 8ll1 MAYER WEINBLATT, Primary Examiner US. Cl. X.R.

8-l11, 252 DIG. 12, 89, 99,105, 186 

